Generac Power Systems CorePower?/ES Generators Installation Manuallines page 6

Existing Wall
36" if the surface has a fire resistant rating of at least one hour per NFPA 37
These guidelines are based upon the
requirements of NFPA 37 and the
manufacturer's requirement for air flow
for proper operation. Local codes may
be different and more restrictive than
what is described here.
60" Minimum
Generator
No windows or openings in the wall permitted
within 5 feet from any point of the generator.
60 inches Minimum Distance All Around
Top of Generator
60" Recommended
Minimum From Ends
Clearance from the ends and front of the generator
should be 36" minimum per NFPA 37. This would
include shrubs, trees and any kind of vegetation.
Clearance at the top should be a minimum of 60
inches from any structure, overhang or projections
from the wall. The generator should not be placed
under a deck or other structure that is closed in and
would limit or contain air flow.